Asterisk - The Open Source Telephony Project GIT-master-2de1a68
enum.c
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1/*
2 * Asterisk -- An open source telephony toolkit.
3 *
4 * Copyright (C) 1999 - 2006, Digium, Inc.
5 *
6 * Mark Spencer <markster@digium.com>
7 *
8 * Funding provided by nic.at
9 *
10 * See http://www.asterisk.org for more information about
11 * the Asterisk project. Please do not directly contact
12 * any of the maintainers of this project for assistance;
13 * the project provides a web site, mailing lists and IRC
14 * channels for your use.
15 *
16 * This program is free software, distributed under the terms of
17 * the GNU General Public License Version 2. See the LICENSE file
18 * at the top of the source tree.
19 */
20
21/*! \file
22 *
23 * \brief ENUM Support for Asterisk
24 *
25 * \author Mark Spencer <markster@digium.com>
26 *
27 * \arg Funding provided by nic.at
28 *
29 * \par Enum standards
30 *
31 * - NAPTR records: http://ietf.nri.reston.va.us/rfc/rfc2915.txt
32 * - DNS SRV records: http://www.ietf.org/rfc/rfc2782.txt
33 * - ENUM http://www.ietf.org/rfc/rfc3761.txt
34 * - ENUM for H.323: http://www.ietf.org/rfc/rfc3762.txt
35 * - ENUM SIP: http://www.ietf.org/rfc/rfc3764.txt
36 * - IANA ENUM Services: http://www.iana.org/assignments/enum-services
37 *
38 * - I-ENUM:
39 * http://tools.ietf.org/wg/enum/draft-ietf-enum-combined/
40 * http://tools.ietf.org/wg/enum/draft-ietf-enum-branch-location-record/
41 *
42 * \par Possible improvement
43 * \todo Implement a caching mechanism for multile enum lookups
44 * - See https://issues.asterisk.org/view.php?id=6739
45 * \todo The service type selection needs to be redone.
46 */
47
48/*! \li \ref enum.c uses the configuration file \ref enum.conf
49 * \addtogroup configuration_file Configuration Files
50 */
51
52/*!
53 * \page enum.conf enum.conf
54 * \verbinclude enum.conf.sample
55 */
56
57/*** MODULEINFO
58 <support_level>core</support_level>
59 ***/
60
61#include "asterisk.h"
62
63#include <sys/socket.h>
64#include <netinet/in.h>
65#include <arpa/nameser.h>
66#ifdef __APPLE__
67#include <arpa/nameser_compat.h>
68#endif
69#include <resolv.h>
70#include <ctype.h>
71#include <regex.h>
72
73#include "asterisk/module.h"
74#include "asterisk/enum.h"
75#include "asterisk/dns.h"
76#include "asterisk/channel.h"
77#include "asterisk/config.h"
78#include "asterisk/utils.h"
79#include "asterisk/manager.h"
80
81#ifdef __APPLE__
82#undef T_NAPTR
83#define T_NAPTR 35
84#endif
85
86#ifdef __APPLE__
87#undef T_TXT
88#define T_TXT 16
89#endif
90
91static char ienum_branchlabel[32] = "i";
92/* how to do infrastructure enum branch location resolution? */
93#define ENUMLOOKUP_BLR_CC 0
94#define ENUMLOOKUP_BLR_TXT 1
95#define ENUMLOOKUP_BLR_EBL 2
97
98/* EBL record provisional type code */
99#define T_EBL 65300
100
102
103/*! \brief Determine the length of a country code when given an E.164 string */
104/*
105 * Input: E.164 number w/o leading +
106 *
107 * Output: number of digits in the country code
108 * 0 on invalid number
109 *
110 * Algorithm:
111 * 3 digits is the default length of a country code.
112 * country codes 1 and 7 are a single digit.
113 * the following country codes are two digits: 20, 27, 30-34, 36, 39,
114 * 40, 41, 43-49, 51-58, 60-66, 81, 82, 84, 86, 90-95, 98.
115 */
116static int cclen(const char *number)
117{
118 int cc;
119 char digits[3] = "";
120
121 if (!number || (strlen(number) < 3)) {
122 return 0;
123 }
124
125 strncpy(digits, number, 2);
126
127 if (!sscanf(digits, "%30d", &cc)) {
128 return 0;
129 }
130
131 if (cc / 10 == 1 || cc / 10 == 7)
132 return 1;
133
134 if (cc == 20 || cc == 27 || (cc >= 30 && cc <= 34) || cc == 36 ||
135 cc == 39 || cc == 40 || cc == 41 || (cc >= 40 && cc <= 41) ||
136 (cc >= 43 && cc <= 49) || (cc >= 51 && cc <= 58) ||
137 (cc >= 60 && cc <= 66) || cc == 81 || cc == 82 || cc == 84 ||
138 cc == 86 || (cc >= 90 && cc <= 95) || cc == 98) {
139 return 2;
140 }
141
142 return 3;
143}
144
146 char txt[1024]; /* TXT record in TXT lookup */
147 int txtlen; /* Length */
148};
149
150/*! \brief Callback for TXT record lookup, /ol version */
151static int txt_callback(void *context, unsigned char *answer, int len, unsigned char *fullanswer)
152{
153 struct txt_context *c = context;
154 unsigned int i;
155
156 c->txt[0] = 0; /* default to empty */
157 c->txtlen = 0;
158
159 if (answer == NULL) {
160 return 0;
161 }
162
163 /* RFC1035:
164 *
165 * <character-string> is a single length octet followed by that number of characters.
166 * TXT-DATA One or more <character-string>s.
167 *
168 * We only take the first string here.
169 */
170
171 i = *answer++;
172 len -= 1;
173
174 if (i > len) { /* illegal packet */
175 ast_log(LOG_WARNING, "txt_callback: malformed TXT record.\n");
176 return 0;
177 }
178
179 if (i >= sizeof(c->txt)) { /* too long? */
180 ast_log(LOG_WARNING, "txt_callback: TXT record too long.\n");
181 i = sizeof(c->txt) - 1;
182 }
183
184 ast_copy_string(c->txt, (char *)answer, i + 1); /* this handles the \0 termination */
185 c->txtlen = i;
186
187 return 1;
188}
189
190/*! \brief Determine the branch location record as stored in a TXT record */
191/*
192 * Input: CC code
193 *
194 * Output: number of digits in the number before the i-enum branch
195 *
196 * Algorithm: Build <ienum_branchlabel>.c.c.<suffix> and look for a TXT lookup.
197 * Return atoi(TXT-record).
198 * Return -1 on not found.
199 *
200 */
201static int blr_txt(const char *cc, const char *suffix)
202{
203 struct txt_context context;
204 char domain[128] = "";
205 char *p1, *p2;
206 int ret;
207
209
210 ast_verb(4, "blr_txt() cc='%s', suffix='%s', c_bl='%s'\n", cc, suffix, ienum_branchlabel);
211
212 if (sizeof(domain) < (strlen(cc) * 2 + strlen(ienum_branchlabel) + strlen(suffix) + 2)) {
214 ast_log(LOG_WARNING, "ERROR: string sizing in blr_txt.\n");
215 return -1;
216 }
217
218 p1 = domain + snprintf(domain, sizeof(domain), "%s.", ienum_branchlabel);
220
221 for (p2 = (char *) cc + strlen(cc) - 1; p2 >= cc; p2--) {
222 if (isdigit(*p2)) {
223 *p1++ = *p2;
224 *p1++ = '.';
225 }
226 }
227 strcat(p1, suffix);
228
229 ast_verb(4, "blr_txt() FQDN for TXT record: %s, cc was %s\n", domain, cc);
230
231 ret = ast_search_dns(&context, domain, C_IN, T_TXT, txt_callback);
232
233 if (ret > 0) {
234 ret = atoi(context.txt);
235
236 if ((ret >= 0) && (ret < 20)) {
237 ast_verb(3, "blr_txt() BLR TXT record for %s is %d (apex: %s)\n", cc, ret, suffix);
238 return ret;
239 }
240 }
241
242 ast_verb(3, "blr_txt() BLR TXT record for %s not found (apex: %s)\n", cc, suffix);
243
244 return -1;
245}
246
248 unsigned char pos;
249 char separator[256]; /* label to insert */
250 int sep_len; /* Length */
251 char apex[256]; /* new Apex */
252 int apex_len; /* Length */
253};
254
255/*! \brief Callback for EBL record lookup */
256static int ebl_callback(void *context, unsigned char *answer, int len, unsigned char *fullanswer)
257{
258 struct ebl_context *c = context;
259 int i;
260
261 c->pos = 0; /* default to empty */
262 c->separator[0] = 0;
263 c->sep_len = 0;
264 c->apex[0] = 0;
265 c->apex_len = 0;
266
267 if (answer == NULL) {
268 return 0;
269 }
270
271 /* draft-lendl-enum-branch-location-record-00
272 *
273 * 0 1 2 3 4 5 6 7
274 * +--+--+--+--+--+--+--+--+
275 * | POSITION |
276 * +--+--+--+--+--+--+--+--+
277 * / SEPARATOR /
278 * +--+--+--+--+--+--+--+--+
279 * / APEX /
280 * +--+--+--+--+--+--+--+--+
281 *
282 * where POSITION is a single byte, SEPARATOR is a <character-string>
283 * and APEX is a <domain-name>.
284 *
285 */
286
287 c->pos = *answer++;
288 len -= 1;
289
290 if ((c->pos > 15) || len < 2) { /* illegal packet */
291 ast_log(LOG_WARNING, "ebl_callback: malformed EBL record.\n");
292 return 0;
293 }
294
295 i = *answer++;
296 len -= 1;
297 if (i > len) { /* illegal packet */
298 ast_log(LOG_WARNING, "ebl_callback: malformed EBL record.\n");
299 return 0;
300 }
301
302 ast_copy_string(c->separator, (char *)answer, i + 1);
303 c->sep_len = i;
304
305 answer += i;
306 len -= i;
307
308 if ((i = dn_expand((unsigned char *)fullanswer, (unsigned char *)answer + len,
309 (unsigned char *)answer, c->apex, sizeof(c->apex) - 1)) < 0) {
310 ast_log(LOG_WARNING, "Failed to expand hostname\n");
311 return 0;
312 }
313 c->apex[i] = 0;
314 c->apex_len = i;
315
316 return 1;
317}
318
319/*! \brief Evaluate the I-ENUM branch as stored in an EBL record */
320/*
321 * Input: CC code
322 *
323 * Output: number of digits in the number before the i-enum branch
324 *
325 * Algorithm: Build <ienum_branchlabel>.c.c.<suffix> and look for an EBL record
326 * Return pos and fill in separator and apex.
327 * Return -1 on not found.
328 *
329 */
330static int blr_ebl(const char *cc, const char *suffix, char *separator, int sep_len, char* apex, int apex_len)
331{
332 struct ebl_context context;
333 char domain[128] = "";
334 char *p1,*p2;
335 int ret;
336
338
339 ast_verb(4, "blr_ebl() cc='%s', suffix='%s', c_bl='%s'\n", cc, suffix, ienum_branchlabel);
340
341 if (sizeof(domain) < (strlen(cc) * 2 + strlen(ienum_branchlabel) + strlen(suffix) + 2)) {
343 ast_log(LOG_WARNING, "ERROR: string sizing in blr_EBL.\n");
344 return -1;
345 }
346
347 p1 = domain + snprintf(domain, sizeof(domain), "%s.", ienum_branchlabel);
349
350 for (p2 = (char *) cc + strlen(cc) - 1; p2 >= cc; p2--) {
351 if (isdigit(*p2)) {
352 *p1++ = *p2;
353 *p1++ = '.';
354 }
355 }
356 strcat(p1, suffix);
357
358 ast_verb(4, "blr_ebl() FQDN for EBL record: %s, cc was %s\n", domain, cc);
359
360 ret = ast_search_dns(&context, domain, C_IN, T_EBL, ebl_callback);
361 if (ret > 0) {
362 ret = context.pos;
363
364 if ((ret >= 0) && (ret < 20)) {
365 ast_verb(3, "blr_txt() BLR EBL record for %s is %d/%s/%s)\n", cc, ret, context.separator, context.apex);
368 return ret;
369 }
370 }
371 ast_verb(3, "blr_txt() BLR EBL record for %s not found (apex: %s)\n", cc, suffix);
372 return -1;
373}
374
375/*! \brief Parse NAPTR record information elements */
376static unsigned int parse_ie(char *data, unsigned int maxdatalen, unsigned char *src, unsigned int srclen)
377{
378 unsigned int len, olen;
379
380 len = olen = (unsigned int) src[0];
381 src++;
382 srclen--;
383
384 if (len > srclen) {
385 ast_log(LOG_WARNING, "ENUM parsing failed: Wanted %u characters, got %u\n", len, srclen);
386 return -1;
387 }
388
389 if (len > maxdatalen)
390 len = maxdatalen;
391 memcpy(data, src, len);
392
393 return olen + 1;
394}
395
396/*! \brief Parse DNS NAPTR record used in ENUM ---*/
397static int parse_naptr(unsigned char *dst, int dstsize, char *tech, int techsize, unsigned char *answer, int len, unsigned char *naptrinput)
398{
399 char tech_return[80];
400 char *oanswer = (char *)answer;
401 char flags[512] = "";
402 char services[512] = "";
403 char *p;
404 char regexp[512] = "";
405 char repl[512] = "";
406 char tempdst[512] = "";
407 char errbuff[512] = "";
408 char delim;
409 char *delim2;
410 char *pattern, *subst, *d;
411 int res;
412 int regexp_len, rc;
413 static const int max_bt = 10; /* max num of regexp backreference allowed, must remain 10 to guarantee a valid backreference index */
414 int size, matchindex; /* size is the size of the backreference sub. */
415 size_t d_len = sizeof(tempdst) - 1;
416 regex_t preg;
417 int re_flags = REG_EXTENDED | REG_NEWLINE;
418 regmatch_t pmatch[max_bt];
419
420 tech_return[0] = '\0';
421 dst[0] = '\0';
422
423 if (len < sizeof(struct naptr)) {
424 ast_log(LOG_WARNING, "NAPTR record length too short\n");
425 return -1;
426 }
427 answer += sizeof(struct naptr);
428 len -= sizeof(struct naptr);
429 if ((res = parse_ie(flags, sizeof(flags) - 1, answer, len)) < 0) {
430 ast_log(LOG_WARNING, "Failed to get flags from NAPTR record\n");
431 return -1;
432 } else {
433 answer += res;
434 len -= res;
435 }
436
437 if ((res = parse_ie(services, sizeof(services) - 1, answer, len)) < 0) {
438 ast_log(LOG_WARNING, "Failed to get services from NAPTR record\n");
439 return -1;
440 } else {
441 answer += res;
442 len -= res;
443 }
444 if ((res = parse_ie(regexp, sizeof(regexp) - 1, answer, len)) < 0) {
445 ast_log(LOG_WARNING, "Failed to get regexp from NAPTR record\n");
446 return -1;
447 } else {
448 answer += res;
449 len -= res;
450 }
451
452 if ((res = dn_expand((unsigned char *)oanswer, (unsigned char *)answer + len, (unsigned char *)answer, repl, sizeof(repl) - 1)) < 0) {
453 ast_log(LOG_WARNING, "Failed to expand hostname\n");
454 return -1;
455 }
456
457 ast_debug(3, "NAPTR input='%s', flags='%s', services='%s', regexp='%s', repl='%s'\n",
458 naptrinput, flags, services, regexp, repl);
459
460
461 if (tolower(flags[0]) != 'u') {
462 ast_log(LOG_WARNING, "NAPTR Flag must be 'U' or 'u'.\n");
463 return -1;
464 }
465
466 p = strstr(services, "e2u+");
467 if (p == NULL)
468 p = strstr(services, "E2U+");
469 if (p){
470 p = p + 4;
471 if (strchr(p, ':')){
472 p = strchr(p, ':') + 1;
473 }
474 ast_copy_string(tech_return, p, sizeof(tech_return));
475 } else {
476
477 p = strstr(services, "+e2u");
478 if (p == NULL)
479 p = strstr(services, "+E2U");
480 if (p) {
481 *p = 0;
482 p = strchr(services, ':');
483 if (p)
484 *p = 0;
485 ast_copy_string(tech_return, services, sizeof(tech_return));
486 }
487 }
488
489 regexp_len = strlen(regexp);
490 if (regexp_len < 7) {
491 ast_log(LOG_WARNING, "Regex too short to be meaningful.\n");
492 return -1;
493 }
494
495 /* this takes the first character of the regexp (which is a delimiter)
496 * and uses that character to find the index of the second delimiter */
497 delim = regexp[0];
498 delim2 = strchr(regexp + 1, delim);
499 if ((delim2 == NULL)
500 || ((regexp[regexp_len - 1] != 'i' || regexp[regexp_len - 2] != delim)
501 && regexp[regexp_len - 1] != delim)) {
502 ast_log(LOG_WARNING, "Regex delimiter error (on \"%s\").\n", regexp);
503 return -1;
504 } else if (strchr((delim2 + 1), delim) == NULL) { /* if the second delimiter is found, make sure there is a third instance. this could be the end one instead of the middle */
505 ast_log(LOG_WARNING, "Regex delimiter error (on \"%s\").\n", regexp);
506 return -1;
507 }
508
509 /* Make the regex case-insensitive if the 'i' flag is present. This assumes you
510 * aren't using 'i' as a delimiter which, although dubious, does not appear to be
511 * explicitly non-compliant */
512 if (regexp[regexp_len - 1] == 'i') {
513 re_flags |= REG_ICASE;
514 }
515
516 pattern = regexp + 1; /* pattern is the regex without the begining and ending delimiter */
517 *delim2 = 0; /* zero out the middle delimiter */
518 subst = delim2 + 1; /* dst substring is everything after the second delimiter. */
519 regexp[regexp_len - 1] = 0; /* zero out the last delimiter */
520
521/*
522 * now do the regex wizardry.
523 */
524
525 if (regcomp(&preg, pattern, re_flags)) {
526 ast_log(LOG_WARNING, "NAPTR Regex compilation error (regex = \"%s\").\n", regexp);
527 return -1;
528 }
529
530 if (preg.re_nsub > ARRAY_LEN(pmatch)) {
531 ast_log(LOG_WARNING, "NAPTR Regex compilation error: too many subs.\n");
532 regfree(&preg);
533 return -1;
534 }
535 /* pmatch is an array containing the substring indexes for the regex backreference sub.
536 * max_bt is the maximum number of backreferences allowed to be stored in pmatch */
537 if ((rc = regexec(&preg, (char *) naptrinput, max_bt, pmatch, 0))) {
538 regerror(rc, &preg, errbuff, sizeof(errbuff));
539 ast_log(LOG_WARNING, "NAPTR Regex match failed. Reason: %s\n", errbuff);
540 regfree(&preg);
541 return -1;
542 }
543 regfree(&preg);
544
545 d = tempdst;
546 d_len--;
547
548 /* perform the backreference sub. Search the subst for backreferences,
549 * when a backreference is found, retrieve the backreferences number.
550 * use the backreference number as an index for pmatch to retrieve the
551 * beginning and ending indexes of the substring to insert as the backreference.
552 * if no backreference is found, continue copying the subst into tempdst */
553 while (*subst && (d_len > 0)) {
554 if ((subst[0] == '\\') && isdigit(subst[1])) { /* is this character the beginning of a backreference */
555 matchindex = (int) (subst[1] - '0');
556 if (matchindex >= ARRAY_LEN(pmatch)) {
557 ast_log(LOG_WARNING, "Error during regex substitution. Invalid pmatch index.\n");
558 return -1;
559 }
560 /* pmatch len is 10. we are guaranteed a single char 0-9 is a valid index */
561 size = pmatch[matchindex].rm_eo - pmatch[matchindex].rm_so;
562 if (size > d_len) {
563 ast_log(LOG_WARNING, "Not enough space during NAPTR regex substitution.\n");
564 return -1;
565 }
566 /* are the pmatch indexes valid for the input length */
567 if ((strlen((char *) naptrinput) >= pmatch[matchindex].rm_eo) && (pmatch[matchindex].rm_so <= pmatch[matchindex].rm_eo)) {
568 memcpy(d, (naptrinput + (int) pmatch[matchindex].rm_so), size); /* copy input substring into backreference marker */
569 d_len -= size;
570 subst += 2; /* skip over backreference characters to next valid character */
571 d += size;
572 } else {
573 ast_log(LOG_WARNING, "Error during regex substitution. Invalid backreference index.\n");
574 return -1;
575 }
576 } else if (isprint(*subst)) {
577 *d++ = *subst++;
578 d_len--;
579 } else {
580 ast_log(LOG_WARNING, "Error during regex substitution.\n");
581 return -1;
582 }
583 }
584 *d = 0;
585 ast_copy_string((char *) dst, tempdst, dstsize);
586 dst[dstsize - 1] = '\0';
587
588 if (*tech != '\0'){ /* check if it is requested NAPTR */
589 if (!strncasecmp(tech, "ALL", techsize)){
590 return 0; /* return or count any RR */
591 }
592 if (!strncasecmp(tech_return, tech, sizeof(tech_return) < techsize ? sizeof(tech_return): techsize)){
593 ast_copy_string(tech, tech_return, techsize);
594 return 0; /* we got our RR */
595 } else { /* go to the next RR in the DNS answer */
596 return 1;
597 }
598 }
599
600 /* tech was not specified, return first parsed RR */
601 ast_copy_string(tech, tech_return, techsize);
602
603 return 0;
604}
605
606/* do not return requested value, just count RRs and return thei number in dst */
607#define ENUMLOOKUP_OPTIONS_COUNT 1
608/* do an ISN style lookup */
609#define ENUMLOOKUP_OPTIONS_ISN 2
610/* do a infrastructure ENUM lookup */
611#define ENUMLOOKUP_OPTIONS_IENUM 4
612/* do a direct DNS lookup: no reversal */
613#define ENUMLOOKUP_OPTIONS_DIRECT 8
614
615/*! \brief Callback from ENUM lookup function */
616static int enum_callback(void *context, unsigned char *answer, int len, unsigned char *fullanswer)
617{
618 struct enum_context *c = context;
619 void *p = NULL;
620 int res;
621
622 res = parse_naptr((unsigned char *)c->dst, c->dstlen, c->tech, c->techlen, answer, len, (unsigned char *)c->naptrinput);
623
624 if (res < 0) {
625 ast_log(LOG_WARNING, "Failed to parse naptr\n");
626 return -1;
627 } else if ((res == 0) && !ast_strlen_zero(c->dst)) { /* ok, we got needed NAPTR */
628 if (c->options & ENUMLOOKUP_OPTIONS_COUNT) { /* counting RRs */
629 c->count++;
630 snprintf(c->dst, c->dstlen, "%d", c->count);
631 } else {
632 if ((p = ast_realloc(c->naptr_rrs, sizeof(*c->naptr_rrs) * (c->naptr_rrs_count + 1)))) {
633 c->naptr_rrs = p;
634 memcpy(&c->naptr_rrs[c->naptr_rrs_count].naptr, answer, sizeof(c->naptr_rrs->naptr));
635 c->naptr_rrs[c->naptr_rrs_count].result = ast_strdup(c->dst);
636 c->naptr_rrs[c->naptr_rrs_count].tech = ast_strdup(c->tech);
637 c->naptr_rrs[c->naptr_rrs_count].sort_pos = c->naptr_rrs_count;
638 c->naptr_rrs_count++;
639 }
640 c->dst[0] = 0;
641 }
642 return 0;
643 }
644
645 return 0;
646}
647
648/* ENUM lookup */
649int ast_get_enum(struct ast_channel *chan, const char *number, char *dst, int dstlen, char *tech, int techlen, char* suffix, char* options, unsigned int record, struct enum_context **argcontext)
650{
651 struct enum_context *context;
652 char tmp[512];
653 char domain[256];
654 char left[128];
655 char middle[128];
656 char naptrinput[128];
657 char apex[128] = "";
658 int ret = -1;
659 /* for ISN rewrite */
660 char *p1 = NULL;
661 char *p2 = NULL;
662 char *p3 = NULL;
663 int k = 0;
664 int i = 0;
665 int z = 0;
666 int spaceleft = 0;
667 struct timeval time_start, time_end;
668
669 if (ast_strlen_zero(suffix)) {
670 ast_log(LOG_WARNING, "ast_get_enum need a suffix parameter now.\n");
671 return -1;
672 }
673
674 ast_debug(2, "num='%s', tech='%s', suffix='%s', options='%s', record=%u\n", number, tech, suffix, options, record);
675
676/*
677 We don't need that any more, that "n" preceding the number has been replaced by a flag
678 in the options paramter.
679 ast_copy_string(naptrinput, number, sizeof(naptrinput));
680*/
681/*
682 * The "number" parameter includes a leading '+' if it's a full E.164 number (and not ISN)
683 * We need to preserve that as the regex inside NAPTRs expect the +.
684 *
685 * But for the domain generation, the '+' is a nuisance, so we get rid of it.
686*/
687 ast_copy_string(naptrinput, number[0] == 'n' ? number + 1 : number, sizeof(naptrinput));
688 if (number[0] == '+') {
689 number++;
690 }
691
692 if (!(context = ast_calloc(1, sizeof(*context)))) {
693 return -1;
694 }
695
696 if ((p3 = strchr(naptrinput, '*'))) {
697 *p3='\0';
698 }
699
700 context->naptrinput = naptrinput; /* The number */
701 context->dst = dst; /* Return string */
702 context->dstlen = dstlen;
703 context->tech = tech;
704 context->techlen = techlen;
705 context->options = 0;
706 context->position = record > 0 ? record : 1;
707 context->count = 0;
708 context->naptr_rrs = NULL;
709 context->naptr_rrs_count = 0;
710
711 /*
712 * Process options:
713 *
714 * c Return count, not URI
715 * i Use infrastructure ENUM
716 * s Do ISN transformation
717 * d Direct DNS query: no reversing.
718 *
719 */
720 if (options != NULL) {
721 if (strchr(options,'s')) {
723 } else if (strchr(options,'i')) {
725 } else if (strchr(options,'d')) {
727 }
728 if (strchr(options,'c')) {
730 }
731 if (strchr(number,'*')) {
733 }
734 }
735 ast_debug(2, "ENUM options(%s): pos=%d, options='%d'\n", options, context->position, context->options);
736 ast_debug(1, "n='%s', tech='%s', suffix='%s', options='%d', record='%d'\n",
737 number, tech, suffix, context->options, context->position);
738
739 /*
740 * This code does more than simple RFC3261 ENUM. All these rewriting
741 * schemes have in common that they build the FQDN for the NAPTR lookup
742 * by concatenating
743 * - a number which needs be flipped and "."-seperated (left)
744 * - some fixed string (middle)
745 * - an Apex. (apex)
746 *
747 * The RFC3261 ENUM is: left=full number, middle="", apex=from args.
748 * ISN: number = "middle*left", apex=from args
749 * I-ENUM: EBL parameters build the split, can change apex
750 * Direct: left="", middle=argument, apex=from args
751 *
752 */
753
754 /* default: the whole number will be flipped, no middle domain component */
755 ast_copy_string(left, number, sizeof(left));
756 middle[0] = '\0';
757 /*
758 * I-ENUM can change the apex, thus we copy it
759 */
760 ast_copy_string(apex, suffix, sizeof(apex));
761 /* ISN rewrite */
762 if ((context->options & ENUMLOOKUP_OPTIONS_ISN) && (p1 = strchr(number, '*'))) {
763 *p1++ = '\0';
764 ast_copy_string(left, number, sizeof(left));
765 ast_copy_string(middle, p1, sizeof(middle) - 1);
766 strcat(middle, ".");
767 ast_debug(2, "ISN ENUM: left=%s, middle='%s'\n", left, middle);
768 /* Direct DNS lookup rewrite */
769 } else if (context->options & ENUMLOOKUP_OPTIONS_DIRECT) {
770 left[0] = 0; /* nothing to flip around */
771 ast_copy_string(middle, number, sizeof(middle) - 1);
772 strcat(middle, ".");
773 ast_debug(2, "DIRECT ENUM: middle='%s'\n", middle);
774 /* Infrastructure ENUM rewrite */
775 } else if (context->options & ENUMLOOKUP_OPTIONS_IENUM) {
776 int sdl = 0;
777 char cc[8];
778 char sep[256], n_apex[256];
779 int cc_len = cclen(number);
780 sdl = cc_len;
782 ast_copy_string(sep, ienum_branchlabel, sizeof(sep)); /* default */
784
785 switch (ebl_alg) {
787 ast_copy_string(cc, number, cc_len); /* cclen() never returns more than 3 */
788 sdl = blr_ebl(cc, suffix, sep, sizeof(sep) - 1, n_apex, sizeof(n_apex) - 1);
789
790 if (sdl >= 0) {
791 ast_copy_string(apex, n_apex, sizeof(apex));
792 ast_debug(2, "EBL ENUM: sep=%s, apex='%s'\n", sep, n_apex);
793 } else {
794 sdl = cc_len;
795 }
796 break;
798 ast_copy_string(cc, number, cc_len); /* cclen() never returns more than 3 */
799 sdl = blr_txt(cc, suffix);
800
801 if (sdl < 0) {
802 sdl = cc_len;
803 }
804 break;
805
806 case ENUMLOOKUP_BLR_CC: /* BLR is at the country-code level */
807 default:
808 sdl = cc_len;
809 break;
810 }
811
812 if (sdl > strlen(number)) { /* Number too short for this sdl? */
813 ast_log(LOG_WARNING, "I-ENUM: subdomain location %d behind number %s\n", sdl, number);
815 return 0;
816 }
817 ast_copy_string(left, number + sdl, sizeof(left));
818
820 ast_copy_string(middle, sep, sizeof(middle) - 1);
821 strcat(middle, ".");
823
824 /* check the space we need for middle */
825 if ((sdl * 2 + strlen(middle) + 2) > sizeof(middle)) {
826 ast_log(LOG_WARNING, "ast_get_enum: not enough space for I-ENUM rewrite.\n");
828 return -1;
829 }
830
831 p1 = middle + strlen(middle);
832 for (p2 = (char *) number + sdl - 1; p2 >= number; p2--) {
833 if (isdigit(*p2)) {
834 *p1++ = *p2;
835 *p1++ = '.';
836 }
837 }
838 *p1 = '\0';
839
840 ast_debug(2, "I-ENUM: cclen=%d, left=%s, middle='%s', apex='%s'\n", cc_len, left, middle, apex);
841 }
842
843 if (strlen(left) * 2 + 2 > sizeof(domain)) {
844 ast_log(LOG_WARNING, "string to long in ast_get_enum\n");
846 return -1;
847 }
848
849 /* flip left into domain */
850 p1 = domain;
851 for (p2 = left + strlen(left); p2 >= left; p2--) {
852 if (isdigit(*p2)) {
853 *p1++ = *p2;
854 *p1++ = '.';
855 }
856 }
857 *p1 = '\0';
858
859 if (chan && ast_autoservice_start(chan) < 0) {
861 return -1;
862 }
863
864 spaceleft = sizeof(tmp) - 2;
865 ast_copy_string(tmp, domain, spaceleft);
866 spaceleft -= strlen(domain);
867
868 if (*middle) {
869 strncat(tmp, middle, spaceleft);
870 spaceleft -= strlen(middle);
871 }
872
873 strncat(tmp,apex,spaceleft);
874 time_start = ast_tvnow();
875 ret = ast_search_dns(context, tmp, C_IN, T_NAPTR, enum_callback);
876 time_end = ast_tvnow();
877
878 ast_debug(2, "profiling: %s, %s, %" PRIi64 " ms\n",
879 (ret == 0) ? "OK" : "FAIL", tmp, ast_tvdiff_ms(time_end, time_start));
880
881 if (ret < 0) {
882 ast_debug(1, "No such number found: %s (%s)\n", tmp, strerror(errno));
883 context->naptr_rrs_count = -1;
884 strcpy(dst, "0");
885 ret = 0;
886 }
887
888 if (context->naptr_rrs_count >= context->position && ! (context->options & ENUMLOOKUP_OPTIONS_COUNT)) {
889 /* sort array by NAPTR order/preference */
890 for (k = 0; k < context->naptr_rrs_count; k++) {
891 for (i = 0; i < context->naptr_rrs_count; i++) {
892 /* use order first and then preference to compare */
893 if ((ntohs(context->naptr_rrs[k].naptr.order) < ntohs(context->naptr_rrs[i].naptr.order)
894 && context->naptr_rrs[k].sort_pos > context->naptr_rrs[i].sort_pos)
895 || (ntohs(context->naptr_rrs[k].naptr.order) > ntohs(context->naptr_rrs[i].naptr.order)
896 && context->naptr_rrs[k].sort_pos < context->naptr_rrs[i].sort_pos)) {
897 z = context->naptr_rrs[k].sort_pos;
898 context->naptr_rrs[k].sort_pos = context->naptr_rrs[i].sort_pos;
899 context->naptr_rrs[i].sort_pos = z;
900 continue;
901 }
902 if (ntohs(context->naptr_rrs[k].naptr.order) == ntohs(context->naptr_rrs[i].naptr.order)) {
903 if ((ntohs(context->naptr_rrs[k].naptr.pref) < ntohs(context->naptr_rrs[i].naptr.pref)
904 && context->naptr_rrs[k].sort_pos > context->naptr_rrs[i].sort_pos)
905 || (ntohs(context->naptr_rrs[k].naptr.pref) > ntohs(context->naptr_rrs[i].naptr.pref)
906 && context->naptr_rrs[k].sort_pos < context->naptr_rrs[i].sort_pos)) {
907 z = context->naptr_rrs[k].sort_pos;
908 context->naptr_rrs[k].sort_pos = context->naptr_rrs[i].sort_pos;
909 context->naptr_rrs[i].sort_pos = z;
910 }
911 }
912 }
913 }
914 for (k = 0; k < context->naptr_rrs_count; k++) {
915 if (context->naptr_rrs[k].sort_pos == context->position - 1) {
916 ast_copy_string(context->dst, context->naptr_rrs[k].result, dstlen);
917 ast_copy_string(context->tech, context->naptr_rrs[k].tech, techlen);
918 break;
919 }
920 }
921 } else if (!(context->options & ENUMLOOKUP_OPTIONS_COUNT)) {
922 context->dst[0] = 0;
923 } else if ((context->options & ENUMLOOKUP_OPTIONS_COUNT)) {
924 snprintf(context->dst, context->dstlen, "%d", context->naptr_rrs_count + context->count);
925 }
926
927 if (chan) {
928 ret |= ast_autoservice_stop(chan);
929 }
930
931 if (!argcontext) {
932 for (k = 0; k < context->naptr_rrs_count; k++) {
933 ast_free(context->naptr_rrs[k].result);
934 ast_free(context->naptr_rrs[k].tech);
935 }
936 ast_free(context->naptr_rrs);
938 } else {
939 *argcontext = context;
940 }
941
942 return ret;
943}
944
945/*! \internal
946 * \brief Format a phone number as a domain in an ENUM-adjacent way.
947 *
948 * Creates a domain name suitable for query by:
949 *
950 * 1. Removing non-digits
951 * 2. Adding a '.' between adjacent digits
952 * 3. Reversing the string
953 * 4. Appending the specified suffix (or e164.arpa if none is specified)
954 */
955static char *format_numeric_domain(const char *number, const char *suffix)
956{
957 char *buffer, *dst;
958 size_t suffix_length;
959 size_t number_length = strlen(number);
960 const char *src = number + number_length - 1;
961
962 if (!suffix) {
963 suffix = "e164.arpa";
964 }
965
966 suffix_length = strlen(suffix);
967
968 dst = buffer = ast_malloc(
969 (number_length * 2) /* We need 2 bytes per input digit */
970 + suffix_length /* ... plus however long the suffix is */
971 + 1 /* ... plus room for the '.' separator */
972 + 1 /* ... and room for the \0 byte at the end */);
973
974 if (buffer) {
975 while (src >= number) {
976 if (isdigit(*src)) {
977 *dst++ = *src;
978 *dst++ = '.';
979 }
980 src--;
981 }
982
983 /* The length arguments below make sure that the \0 byte is copied into
984 the final string */
985 if (*suffix == '.') {
986 memcpy(dst, &suffix[1], suffix_length);
987 } else {
988 memcpy(dst, suffix, suffix_length + 1);
989 }
990 }
991
992 return buffer;
993}
994
995int ast_get_txt(struct ast_channel *chan, const char *number, char *txt, int txtlen, char *suffix)
996{
997 struct txt_context context;
998 char *domain;
999 int ret;
1000 int autoservice = 0;
1001
1002 ast_debug(4, "ast_get_txt: Number = '%s', suffix = '%s'\n", number, suffix);
1003
1004 domain = format_numeric_domain(number, suffix);
1005 if (!domain) {
1006 return -1;
1007 }
1008
1009 if (chan) {
1010 /* DNS might take a while, so service the channel while we're blocked */
1011 autoservice = !ast_autoservice_start(chan);
1012 }
1013
1014 ret = ast_search_dns(&context, domain, C_IN, T_TXT, txt_callback);
1015 if (ret > 0) {
1017 } else {
1018 ast_debug(2, "No such number found in ENUM: %s (%s)\n", domain, strerror(errno));
1019 }
1020
1021 if (autoservice) {
1023 }
1024
1025 ast_free(domain);
1026 return 0;
1027}
1028
1029/*! \brief Initialize the ENUM support subsystem */
1031{
1032 struct ast_config *cfg;
1033 const char *string;
1034 struct ast_flags config_flags = { reload ? CONFIG_FLAG_FILEUNCHANGED : 0 };
1035
1036 if ((cfg = ast_config_load2("enum.conf", "enum", config_flags)) == CONFIG_STATUS_FILEUNCHANGED)
1037 return 0;
1039 return 0;
1040 }
1041
1042 /* Destroy existing list */
1044 if (cfg) {
1045 if ((string = ast_variable_retrieve(cfg, "ienum", "branchlabel"))) {
1047 }
1048
1049 if ((string = ast_variable_retrieve(cfg, "ienum", "ebl_alg"))) {
1050 ebl_alg = ENUMLOOKUP_BLR_CC; /* default */
1051
1052 if (!strcasecmp(string, "txt"))
1054 else if (!strcasecmp(string, "ebl"))
1056 else if (!strcasecmp(string, "cc"))
1058 else
1059 ast_log(LOG_WARNING, "No valid parameter for ienum/ebl_alg.\n");
1060 }
1061 ast_config_destroy(cfg);
1062 }
1064 return 0;
1065}
1066
1067static int load_module(void)
1068{
1070}
1071
1072static int unload_module(void)
1073{
1074 return 0;
1075}
1076
1077static int reload_module(void)
1078{
1079 return private_enum_init(1);
1080}
1081
1083 .support_level = AST_MODULE_SUPPORT_CORE,
1084 .load = load_module,
1085 .unload = unload_module,
1087 .load_pri = AST_MODPRI_CORE,
1088 .requires = "extconfig",
Asterisk main include file. File version handling, generic pbx functions.
#define ast_free(a)
Definition: astmm.h:180
#define ast_realloc(p, len)
A wrapper for realloc()
Definition: astmm.h:226
#define ast_strdup(str)
A wrapper for strdup()
Definition: astmm.h:241
#define ast_calloc(num, len)
A wrapper for calloc()
Definition: astmm.h:202
#define ast_malloc(len)
A wrapper for malloc()
Definition: astmm.h:191
#define ast_log
Definition: astobj2.c:42
static int tmp()
Definition: bt_open.c:389
static int answer(void *data)
Definition: chan_pjsip.c:683
General Asterisk PBX channel definitions.
int ast_autoservice_stop(struct ast_channel *chan)
Stop servicing a channel for us...
Definition: autoservice.c:266
int ast_autoservice_start(struct ast_channel *chan)
Automatically service a channel for us...
Definition: autoservice.c:200
DNS support for Asterisk.
int ast_search_dns(void *context, const char *dname, int class, int type, int(*callback)(void *context, unsigned char *answer, int len, unsigned char *fullanswer))
Perform DNS lookup (used by DNS, enum and SRV lookups)
Definition: dns.c:491
static int private_enum_init(int reload)
Initialize the ENUM support subsystem.
Definition: enum.c:1030
#define T_EBL
Definition: enum.c:99
static int parse_naptr(unsigned char *dst, int dstsize, char *tech, int techsize, unsigned char *answer, int len, unsigned char *naptrinput)
Parse DNS NAPTR record used in ENUM —.
Definition: enum.c:397
static int blr_ebl(const char *cc, const char *suffix, char *separator, int sep_len, char *apex, int apex_len)
Evaluate the I-ENUM branch as stored in an EBL record.
Definition: enum.c:330
static int txt_callback(void *context, unsigned char *answer, int len, unsigned char *fullanswer)
Callback for TXT record lookup, /ol version.
Definition: enum.c:151
#define ENUMLOOKUP_BLR_TXT
Definition: enum.c:94
static char ienum_branchlabel[32]
Definition: enum.c:91
#define ENUMLOOKUP_BLR_CC
Definition: enum.c:93
static unsigned int parse_ie(char *data, unsigned int maxdatalen, unsigned char *src, unsigned int srclen)
Parse NAPTR record information elements.
Definition: enum.c:376
static int ebl_callback(void *context, unsigned char *answer, int len, unsigned char *fullanswer)
Callback for EBL record lookup.
Definition: enum.c:256
int ast_get_enum(struct ast_channel *chan, const char *number, char *dst, int dstlen, char *tech, int techlen, char *suffix, char *options, unsigned int record, struct enum_context **argcontext)
Lookup entry in ENUM.
Definition: enum.c:649
static int reload_module(void)
Definition: enum.c:1077
#define ENUMLOOKUP_OPTIONS_COUNT
Definition: enum.c:607
static char * format_numeric_domain(const char *number, const char *suffix)
Definition: enum.c:955
#define ENUMLOOKUP_BLR_EBL
Definition: enum.c:95
static int enum_callback(void *context, unsigned char *answer, int len, unsigned char *fullanswer)
Callback from ENUM lookup function.
Definition: enum.c:616
static int cclen(const char *number)
Determine the length of a country code when given an E.164 string.
Definition: enum.c:116
int ast_get_txt(struct ast_channel *chan, const char *number, char *txt, int txtlen, char *suffix)
Lookup DNS TXT record (used by app TXTCIDnum)
Definition: enum.c:995
static ast_mutex_t enumlock
Definition: enum.c:101
#define ENUMLOOKUP_OPTIONS_ISN
Definition: enum.c:609
static int blr_txt(const char *cc, const char *suffix)
Determine the branch location record as stored in a TXT record.
Definition: enum.c:201
static int load_module(void)
Definition: enum.c:1067
#define ENUMLOOKUP_OPTIONS_IENUM
Definition: enum.c:611
static int unload_module(void)
Definition: enum.c:1072
#define ENUMLOOKUP_OPTIONS_DIRECT
Definition: enum.c:613
static int ebl_alg
Definition: enum.c:96
DNS and ENUM functions.
static int len(struct ast_channel *chan, const char *cmd, char *data, char *buf, size_t buflen)
Configuration File Parser.
struct ast_config * ast_config_load2(const char *filename, const char *who_asked, struct ast_flags flags)
Load a config file.
Definition: main/config.c:3321
#define CONFIG_STATUS_FILEMISSING
#define CONFIG_STATUS_FILEUNCHANGED
#define CONFIG_STATUS_FILEINVALID
void ast_config_destroy(struct ast_config *cfg)
Destroys a config.
Definition: extconf.c:1289
const char * ast_variable_retrieve(struct ast_config *config, const char *category, const char *variable)
Definition: main/config.c:783
@ CONFIG_FLAG_FILEUNCHANGED
#define ast_debug(level,...)
Log a DEBUG message.
#define ast_verb(level,...)
#define LOG_WARNING
#define ast_mutex_unlock(a)
Definition: lock.h:190
#define ast_mutex_lock(a)
Definition: lock.h:189
#define AST_MUTEX_DEFINE_STATIC(mutex)
Definition: lock.h:520
int errno
The AMI - Asterisk Manager Interface - is a TCP protocol created to manage Asterisk with third-party ...
Asterisk module definitions.
@ AST_MODFLAG_LOAD_ORDER
Definition: module.h:317
@ AST_MODFLAG_GLOBAL_SYMBOLS
Definition: module.h:316
#define AST_MODULE_INFO(keystr, flags_to_set, desc, fields...)
Definition: module.h:543
@ AST_MODPRI_CORE
Definition: module.h:324
@ AST_MODULE_SUPPORT_CORE
Definition: module.h:121
#define ASTERISK_GPL_KEY
The text the key() function should return.
Definition: module.h:46
@ AST_MODULE_LOAD_FAILURE
Module could not be loaded properly.
Definition: module.h:102
@ AST_MODULE_LOAD_SUCCESS
Definition: module.h:70
const char * string
Definition: presencestate.c:71
static int reload(void)
#define NULL
Definition: resample.c:96
static force_inline int attribute_pure ast_strlen_zero(const char *s)
Definition: strings.h:65
void ast_copy_string(char *dst, const char *src, size_t size)
Size-limited null-terminating string copy.
Definition: strings.h:425
Main Channel structure associated with a channel.
Structure used to handle boolean flags.
Definition: utils.h:199
char apex[256]
Definition: enum.c:251
char separator[256]
Definition: enum.c:249
unsigned char pos
Definition: enum.c:248
int apex_len
Definition: enum.c:252
int sep_len
Definition: enum.c:250
int dstlen
Definition: enum.h:44
char * naptrinput
Definition: enum.h:49
char * dst
Definition: enum.h:43
int techlen
Definition: enum.h:46
char * tech
Definition: enum.h:45
Definition: enum.h:30
Number structure.
Definition: app_followme.c:154
int txtlen
Definition: enum.c:147
char txt[1024]
Definition: enum.c:146
static struct test_options options
static struct test_val d
static struct test_val c
int64_t ast_tvdiff_ms(struct timeval end, struct timeval start)
Computes the difference (in milliseconds) between two struct timeval instances.
Definition: time.h:107
struct timeval ast_tvnow(void)
Returns current timeval. Meant to replace calls to gettimeofday().
Definition: time.h:159
Utility functions.
#define ARRAY_LEN(a)
Definition: utils.h:666